GLTF Model Support

[AtlasProgramming]

Considerations for GLTF Model Support (not a complete list)

• Ability to load models that are packaged with the release or remotely
• Support replacing extruded buildings with models
• Local caching of remote models
• Ability to check for updated models for hosted models (e.g. HEAD request)
• Support animations/lighting/etc (e.g. things like the animating the London Eye)
• How is metadata supported in the tiles
• How models are culled from the scene (e.g. if a tile is not in the frustum, but contains a model that is, how is that handled)
• Caching of models in memory and culling resources as needed
• How lighting environmental lighting is factored in
• What the base units are for scaling (e.g. models in meters are natively supported, but if something is in another scale, how is that passed in)
• Multiple LODs for models based on screen size (similar to mip-maps)
• How to handle resources that fail to load
• How to pass in rotation around the model's origin
• How to handle rendering models within extruded buildings